Rapid identification of carbapenemases by CarbAcineto NP test and the rate of beta-lactamases among Acinetobacter baumannii from a teaching hospital

Abstract

Background and Objectives: Acinetobacter baumannii has emerged as a major organism accounting for hospital acquired infections particularly in intensive care units. Due to production of different kinds of beta lactamases these bacteria have developed drug resistance rendering the treatment of such infections very difficult and expensive. Rapid identification of A. baumannii producing such beta-lactamases is the need of the hour in reducing morbidity and mortality associated with A. baumannii infections.
 Materials and Methods: A. baumannii was isolated from clinical samples like endotracheal aspirates, sputum, urine, exu- dates using standard culture techniques. Identification and drug sensitivity was done using Vitek 2 system. All the isolates were subjected to detection of ESBLs using phenotypic confirmatory test, plasmid mediated AmpC beta- lactamase by AmpC disc test, Carbapenemase production by CarbAcineto NP Test and Modified hodge method.
 Results: 149 A. baumannii isolates were analysed for antimicrobial susceptibility and various beta-lactamase production. Results were evaluated for statistical significance using Chi-Square and P value. 81.8% of isolates were from male patients with majority of them above 50 years of age. 88.5% of samples were from ventilator associated pneumonia patients. 83.8% of isolates were sensitive to tigecycline. Only 10% to 12% of isolates were sensitive to carbapenems. 23.4% of isolates were ESBL producers and 46.9% of them were AmpC producers. Modified Hodge test method identified 63.7% of A. baumannii as carbapenemase producers where as CarbAcineto NP test identified 63% and exibiting 94.74% sensitivity, 93.22% specificity when compared to Modified Hodge test.
 Conclusion: Multidrug resistant Acinetobacter spp. is on the rise. Present study showed that high percentage of drug resis- tance in A. baumannii could be due to production of ESBLs, AmpC and carbapenemases. Among all beta lactamases car- bapenemase producers are more and quickly raising in A. baumannii. Rapid, cost effective assay which can be adopted in all clinical laboratories is critical to prevent their further transmission particularly in hospital environment.

Phenotypic Characterization and Prevalence of Carbapenemase-Producing <i>Acinetobacter baumanii</i> Isolates in Four Health Facilities in Cameroon

“…In order to fight against the emergence and spread of multiresistant bacteria, this study aimed to determine the prevalence and risk factors of carbapene- In the present study, 88 (52.69%) clinical isolates included were from male patients with highest number of isolates from patients aged between 10 -39 years old. This is in line with a recent study realized by Rao et al which reported a high proportion of males (81.8%) [17]. These findings suggest that male and elderly were more vulnerable for infections in both studies.…”

Phenotypic Characterization and Prevalence of Carbapenemase-Producing <em>Acinetobacter baumanii </em>Isolates in Four Health Facilities in Cameroon<strong> </strong>

“…In the present study 88 (52.69%) clinical isolates included were from male patients with highest number of isolates from patients aged between 10-39 years old. In accordance to the current study, Rao et al also observed male predominance (81.8%) [15]. These findings suggest that male elderly were more vulnerable for infections in both the studies.…”